feat(api): admin backoffice router — meshes, sessions, invites, audit

Extends the Hono adminRouter with four new read-only mesh admin modules:
meshes, sessions, invites, audit. Each ships {queries,router}.ts following
the existing users/organizations/customers pattern (paginated Drizzle
transactions, getOrderByFromSort sorting, ilike search, enum filters).

- GET /admin/meshes — paginated list with owner join + member count subquery
- GET /admin/meshes/:id — detail: members, presences, invites, last 50 audit
  events (returns {mesh: null,...} shell on not-found to stay single-shape
  for Hono RPC inference)
- GET /admin/sessions — live WS presences across every mesh, joined to
  member/mesh for display, status + active/disconnected filters
- GET /admin/invites — invite tokens w/ mesh + createdBy user joins,
  revoked/expired filters
- GET /admin/audit — mesh audit log with eventType/meshId/date filters

Summary endpoint extended: new GET /admin/summary/mesh returns
{meshes, activeMeshes, totalPresences, activePresences, messages24h}.
Messages24h derived from audit_log where event_type='message_sent'
in the past 24h.

Schemas live in packages/api/src/schema/mesh-admin.ts, re-exported from
the schema barrel. All mesh/role/transport enums mirror the DB enums
from packages/db/src/schema/mesh.ts.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/api/src/modules/admin/router.ts

@@ -2,10 +2,23 @@ import { Hono } from "hono";
 
 import { enforceAdmin, enforceAuth } from "../../middleware";
 
+import { auditRouter } from "./audit/router";
+import { getMessages24hCount } from "./audit/queries";
 import { getCustomersCount } from "./customers/queries";
 import { customersRouter } from "./customers/router";
+import { invitesRouter } from "./invites/router";
+import {
+  getActiveMeshesCount,
+  getMeshesCount,
+} from "./meshes/queries";
+import { meshesRouter } from "./meshes/router";
 import { getOrganizationsCount } from "./organizations/queries";
 import { organizationsRouter } from "./organizations/router";
+import {
+  getActivePresencesCount,
+  getPresencesCount,
+} from "./sessions/queries";
+import { sessionsRouter } from "./sessions/router";
 import { getUsersCount } from "./users/queries";
 import { usersRouter } from "./users/router";
 
@@ -15,6 +28,10 @@ export const adminRouter = new Hono()
   .route("/users", usersRouter)
   .route("/organizations", organizationsRouter)
   .route("/customers", customersRouter)
+  .route("/meshes", meshesRouter)
+  .route("/sessions", sessionsRouter)
+  .route("/invites", invitesRouter)
+  .route("/audit", auditRouter)
   .get("/summary", async (c) => {
     const [users, organizations, customers] = await Promise.all([
       getUsersCount(),
@@ -23,4 +40,22 @@ export const adminRouter = new Hono()
     ]);
 
     return c.json({ users, organizations, customers });
+  })
+  .get("/summary/mesh", async (c) => {
+    const [meshes, activeMeshes, totalPresences, activePresences, messages24h] =
+      await Promise.all([
+        getMeshesCount(),
+        getActiveMeshesCount(),
+        getPresencesCount(),
+        getActivePresencesCount(),
+        getMessages24hCount(),
+      ]);
+
+    return c.json({
+      meshes,
+      activeMeshes,
+      totalPresences,
+      activePresences,
+      messages24h,
+    });
   });